Rogues Exposed

by Kara Furlong and David F. Salisbury 813 views No Comment Print  E-mail

Holley Bockelmann

Research by Assistant Professor of Astronomy Kelly Holley-Bockelmann indicates that there may be hundreds of nearly impossible-to-spot black holes careening around the galaxy. Because these rogue black holes can’t be directly observed, Holley-Bockelmann’s research simulates their behavior. She uses the supercomputer at Vanderbilt’s Advanced Computing Center for Research and Education (ACCRE) to run simulations to test her theories. 

Her research proposes that the merger of two black holes that are rotating at different speeds (or are different sizes) produces a big kick, pushing the newly merged black hole away in an arbitrary direction at velocities as high as 4,000 kilometers per second. 

“This is much higher than anyone predicted,” the astronomer says. If the roughly 200 globular clusters in the Milky Way have indeed spawned black holes, this means that hundreds of them are probably wandering invisibly around the Milky Way, waiting to engulf the nebulae, stars and planets unfortunate enough to cross their paths.

Fortunately, the existence of a few rogue black holes in the neighborhood does not present a major danger. “These rogue black holes are extremely unlikely to do any damage to us in the lifetime of the universe,” Holley-Bockelmann stresses. “Their danger zone is really tiny, only a few hundred kilometers.”

Holley-Bockelmann said to think of her findings this way: “What I do on a day-to-day basis is try to figure out what the link is between a galaxy and the black hole that lives within it. Does it change the shape of the galaxy in any way? Does it affect the way the galaxy moves and evolves and ultimately dies? My job is to figure out how the black hole and the galaxy communicate with one another.”

Holley-Bockelmann presented the research, which was conducted in collaboration with scientists at Penn State University and the University of Michigan, at a meeting of the American Astronomical Society.

photo credit: John Russell